(Meth)acrylate, polymer and resist composition

Abstract

A polymer contains a constituent unit having a specific acetal skeleton. This polymer is able to be used as a resist resin in DUV excimer laser lithography, electron beam lithography, EUV lithography, or the like.

The invention claimed is: 
     
       1. A copolymer consisting essentially of:
 a constituent unit consisting of a monomer represented by the following formula (1): 
 
       
         
           
           
               
               
           
         
       
       wherein
 R represents a hydrogen atom or a methyl group, 
 R 1  represents a methyl group and 
 R 2  represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, or 
 R 1  and R 2  are combined with each other to form a ring structure; 
 A 1  represents a single bond, alkylene, oxyalkylene, —C(O)O—, or —CH 2 CH 2 OC(O)—; 
 A 2  represents a single bond, alkylene, oxyalkylene, —CO—, —C(O)O—, or —C(O)OCH 2 CH 2 —; and 
 Z represents a cyclohexane ring, norbornane ring, bicyclo[2.2.2]octane ring, or tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodecane ring, all of which may have a substituent; 
 one or more constituent units derived from a monomer having a lactone structure in a molecule, and, 
 one or more constituent units derived from a monomer containing an alicylic skeleton having a hydroxy group or a cyano group in a molecule, and 
 one or more constituent units derived from monomers selected from the group consisting of monomers represented by the following formulae (6-1), (6-2), (6-4), (6-5), (6-14), (6-15), (6-16), (6-18), (6-57), (6-58), (6-65), (6-66), and (6-67): 
 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein R represents a hydrogen atom or a methyl group. 
       
     
     
       2. A copolymer according to  claim 1 , further comprising one or more constituent units derived from monomers selected from the group consisting of monomers represented by the following formulae (6-22) and (6-64): 
       
         
           
           
               
               
           
         
         wherein R represents a hydrogen atom or a methyl group. 
       
     
     
       3. A resin composition comprising the copolymer according to  claim 1 . 
     
     
       4. A pattern forming method comprising the steps of:
 coating the resist composition according to  claim 1  on a to-be-processed substrate, 
 exposing the coated substrate to light having a wavelength of 250 nm or less, and 
 developing the exposed substrate using a developing solution to form a pattern. 
 
     
     
       5. A copolymer consisting essentially of:
 a constituent unit consisting of a monomer represented by the following formula (1): 
 
       
         
           
           
               
               
           
         
       
       wherein
 R represents a hydrogen atom or a methyl group, 
 R 1  represents a methyl group and 
 R 2  represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, or 
 R 1  and R 2  are combined with each other to form a ring structure; 
 A 1  represents a single bond, alkylene, oxyalkylene, —C(O)O—, or —CH 2 CH 7 OC(O)—; 
 A 2  represents a single bond, alkylene, oxyalkylene, —CO—, —C(O)O—, or —C(O)OCH 2 CH 2 —; and 
 Z represents a cyclohexane ring, norbornane ring, bicyclo[2.2.2]octane ring, or tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodecane ring, each of which may have a substituent; 
 one or more units derived from a monomer having a lactone structure in a molecule, and, 
 one or more constituent units derived from a monomer containing an alicylic skeleton having a hydroxy group or a cyano group in a molecule; 
 wherein said one or more constituent units derived from a monomer containing an alicylic skeleton having a hydroxy group or a cyano group in a molecule are selected from constituent units derived from a monomer selected from the group consisting of: monomers represented by the following formulae (6-19) and (6-74): 
 
       
         
           
           
               
               
           
         
         wherein R represents a hydrogen atom or a methyl group. 
       
     
     
       6. A copolymer consisting essentially of: a constituent unit derived from a monomer represented by the following formula (3): 
       
         
           
           
               
               
           
         
       
       wherein
 R represents a hydrogen atom or a methyl group, 
 R 1  represents a methyl group and 
 R 2  represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, 
 A 1  represents a single bond, alkylene, oxyalkylene, —C(O)O—, or —CH 2 CH 2 OC(O)—; 
 A 2  represents a single bond, alkylene, oxyalkylene, —CO—, —C(O)O—, or —C(O)OCH 2 CH 2 —; and 
 Z represents a cyclohexane ring which may have a substituent; and 
 one or more constituent units derived from one or more monomers containing a lactone structure in the molecule. 
 
     
     
       7. A copolymer consisting essentially of: a constituent unit derived from a monomer represented by the following formula (3): 
       
         
           
           
               
               
           
         
       
       wherein
 R represents a hydrogen atom or a methyl group, 
 R 1  represents a methyl group and 
 R 2  represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, 
 A 1  represents a single bond, alkylene, oxyalkylene, —C(O)O—, or —CH 2 CH 2 OC(O)—; 
 A2 represents a single bond, alkylene, oxyalkylene, —CO—, —C(O)O—, or —C(O)OCH 2 CH 2 —; and 
 Z represents bicyclo[2.2.2]octane ring which may have a substituent; and 
 one or more constituent units derived from one or more monomers containing a lactone structure in the molecule. 
 
     
     
       8. A copolymer consisting essentially of:
 25 to 70 mol % of a constituent unit represented by the following formula (1): 
 
       
         
           
           
               
               
           
         
       
       wherein
 R represents a hydrogen atom or a methyl group, 
 R 1  represents a methyl group and 
 R 2  represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, or 
 R 1  and R 2  are combined with each other to form a ring structure; 
 A 1  represents a single bond, alkylene, oxyalkylene, —C(O)O—, or —CH 2 CH 2 OC(O)—; 
 A 2  represents a single bond, alkylene, oxyalkylene, —CO—, —C(O)O—, or —C(O)OCH 2 CH 2 —; and 
 Z represents a norbornane ring which may have a substituent; 
 25 to 70 mol % of a constituent unit derived from at least one monomer containing a lactone structure in the molecule; and 
 5 to 20 mol % of a constituent unit derived from at least one monomer selected from the group consisting of a monomer containing alicyclic skeleton having a hydroxy group and a monomer containing alicyclic skeleton having a cyano group. 
 
     
     
       9. A copolymer consisting essentially of:
 25 to 70 mol % of a constituent unit represented by the following formula (1): 
 
       
         
           
           
               
               
           
         
       
       wherein
 R represents a hydrogen atom or a methyl group, 
 R 1  represents a methyl group and 
 R 2  represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, or 
 R 1  and R 2  are combined with each other to form a ring structure; 
 A 1  represents a single bond, alkylene, oxyalkylene, —C(O)O—, or —CH 2 CH 2 OC(O)—; 
 A 2  represents a single bond, alkylene, oxyalkylene, —CO—, —C(O)O—, or —C(O)OCH 2 CH 2 —; and 
 Z represents a bicyclo[2.2.2]octane ring which may have a substituent; 
 25 to 70 mol % of a constituent unit derived from at least one monomer containing a lactone structure in the molecule; and 
 5 to 20 mol % of a constituent unit derived from at least one monomer selected from the group consisting of a monomer containing alicyclic skeleton having a hydroxy group and a monomer containing alicyclic skeleton having a cyano group. 
 
     
     
       10. A copolymer consisting essentially of:
 25 to 70 mol % of a constituent unit represented by the following formula (1): 
 
       
         
           
           
               
               
           
         
       
       wherein
 R represents a hydrogen atom or a methyl group, 
 R 1  represents a methyl group and 
 R 2  represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, or 
 R 1  and R 2  are combined with each other to form a ring structure; 
 A 1  represents a single bond, alkylene, oxyalkylene, —C(O)O—, or —CH 2 CH 2 OC(O)—; 
 A 2  represents a single bond, alkylene, oxyalkylene, —CO—, —C(O)O—, or —C(O)OCH 2 CH 2 —; and 
 Z represents a tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodecane ring which may have a substituent; 
 25 to 70 mol % of a constituent unit derived from at least one monomer containing a lactone structure in the molecule; and 
 5 to 20 mol % of a constituent unit derived from at least one monomer selected from the group consisting of a monomer containing alicyclic skeleton having a hydroxy group and a monomer containing alicyclic skeleton having a cyano group. 
 
     
     
       11. A copolymer consisting essentially of:
 a constituent unit consisting of a monomer represented by the following formula (1): 
 
       
         
           
           
               
               
           
         
       
       wherein
 R represents a hydrogen atom or a methyl group, 
 R 1  represents a methyl group and 
 R 2  represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, or 
 R 1  and R 2  are combined with each other to form a ring structure; 
 A 1  represents a single bond, alkylene, oxyalkylene, —C(O)O—, or —CH 2 CH 2 OC(O)—; 
 A 2  represents a single bond, alkylene, oxyalkylene, —CO—, —C(O)O—, or —C(O)OCH 2 CH 2 —; and 
 Z represents a cyclohexane ring, norbornane ring, bicyclo[2.2.2]octane ring, or tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodecane ring, each of which may have a substituent; 
 one or more units derived from a monomer having a lactone structure in a molecule, 
 one or more constituent units derived from monomers selected from the group consisting of: monomers represented by the following formulae (6-1), (6-2), (6-4), (6-5), (6-14), (6-15), (6-16), (6-18), (6-57), (6-58), (6-65), (6-66), and (6-67): 
 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein R represents a hydrogen atom or a methyl group, and 
         one or more constituent units derived from monomers selected from the group consisting of monomers represented by the following formulae (6-22) and (6-64): 
       
       
         
           
           
               
               
           
         
         wherein R represents a hydrogen atom or a methyl group. 
       
     
     
       12. A copolymer consisting essentially of:
 a constituent unit consisting of a monomer represented by the following formula (1): 
 
       
         
           
           
               
               
           
         
       
       wherein
 R represents a hydrogen atom or a methyl group, 
 R 1  represents a methyl group and 
 R 2  represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, or 
 R 1  and R 2  are combined with each other to form a ring structure; 
 A 1  represents a single bond, alkylene, oxyalkylene, —C(O)O—, or —CH 2 CH 2 OC(O)—; 
 A 2  represents a single bond, alkylene, oxyalkylene, —CO—, —C(O)O—, or —C(O)OCH 2 CH 2 —; and 
 Z represents a cyclohexane ring, norbornane ring, bicyclo[2.2.2]octane ring, or tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodecane ring, all of which may have a substituent; 
 one or more units derived from a monomer having a lactone structure in a molecule, 
 one or more constituent units derived from a monomer containing an alicylic skeleton having a hydroxy group or a cyano group in a molecule, and 
 one or more constituent units derived from monomers selected from the group consisting of monomers represented by the following formulae (6-22) and (6-64): 
 
       
         
           
           
               
               
           
         
         wherein R represents a hydrogen atom or a methyl group.